Help Center/ GaussDB(DWS)/ SQL Syntax Reference/ SQL Syntax Reference (9.1.0.x)/ DDL Syntax/ ALTER RESOURCE POOL
Updated on 2025-07-22 GMT+08:00
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ALTER RESOURCE POOL

Function

ALTER RESOURCE POOL changes the Cgroup of a resource pool.

Precautions

Users having the ALTER permission can modify resource pools.

Syntax

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ALTER RESOURCE POOL pool_name
    WITH ({MEM_PERCENT=pct | CONTROL_GROUP='group_name' | ACTIVE_STATEMENTS=stmt | MAX_DOP = dop | MEMORY_LIMIT='memory_size' | io_limits=io_limits | io_priority='priority' | nodegroup='nodegroup_name' | except_rule='except_rule' | weight=bandwidth_weight | enable_concurrency_scaling=boolean}[, ... ]);

Parameter Description

Table 1 ALTER RESOURCE POOL parameters

Parameter

Description

Value Range

pool_name

Specifies the name of the resource pool to be modified.

Name of an existing resource pool

group_name

Specifies the name of a Cgroup.

Name of an existing Cgroup

stmt

Specifies the maximum number of statements that can be concurrently executed in a resource pool.

Numeral type. The value ranges from –1 to INT_MAX.

dop

Specifies the maximum number of simple SQL statements that can be concurrently executed in a resource pool.

Numeral type. The value ranges from –1 to INT_MAX.

memory_size

Specifies the estimated maximum memory for a resource pool.

Value range: a string

  • default: The memory limit is half of the resource pool memory.
  • unlimited: no limit.
  • Value range: 1 KB to 2047 GB.

mem_percent

Specifies the proportion of available resource pool memory to the total memory or group user memory.

The value of mem_percent for a common user is an integer ranging from 0 to 100. The default value is 0.

io_limits

This parameter has been discarded in the 8.1.2 cluster version and is reserved for compatibility with earlier versions.

-

io_priority

This parameter has been discarded in the 8.1.2 cluster version and is reserved for compatibility with earlier versions.

-

except_rule

Specifies the exception rule set.

-

weight

Specifies the network bandwidth weight of a resource pool.

-

enable_concurrency_scaling

Specifies whether to enable the elastic concurrency expansion function. This function is supported only by clusters of version 9.1.0.100 or later. The default value is false.

true or false

  • true indicates that the elastic concurrent expansion function of jobs in the resource pool is enabled.
  • false indicates that the elastic concurrent expansion function of jobs in the resource pool is disabled.
  • You can use double quotation marks (") or single quotation marks (') to set the Cgroup name group_name.
  • The value of group_name is case-sensitive.
  • When group_name is not specified, the default value "Medium" is used. It is the "Medium" Timeshare Cgroup

    of the DefaultClass Cgroup.

  • If a database user specifies the Timeshare string (Rush, High, Medium, or Low) in the syntax, for example, if control_group is set to High, the resource pool will be associated with the High Timeshare Cgroup under DefaultClass.

Examples

Create an example resource pool pool_test, whose Cgroup is Medium Timeshare Workload under DefaultClass.

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DROP RESOURCE POOL IF EXISTS pool_test;
CREATE RESOURCE POOL pool_test;

Specify High Timeshare Workload under DefaultClass as the Cgroup for the resource pool pool_test.

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ALTER RESOURCE POOL pool_test WITH (CONTROL_GROUP="High");

Disable the elastic concurrent expansion function for jobs in a specified resource pool.

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ALTER RESOURCE POOL pool_test WITH (enable_concurrency_scaling=false);

Helpful Links

CREATE RESOURCE POOL and DROP RESOURCE POOL

Parent Topic: DDL Syntax